Dynamic real-time magnetic resonance imaging sequence designer

ABSTRACT

A system and method for facilitating RF pulse sequence generation and modification and for real-time sequence input modification for use in conjunction with magnetic resonance imaging equipment. A graphical user interface is provided through a display coupled to a digital computer operating as the primary control system for a magnetic resonance imaging scanner and associated hardware. Through the graphical user interface, an operator may choose or design sequences of radiofrequency pulses, gradient waveforms and other input parameters for the magnetic resonance imaging apparatus. Real-time information is also communicated to the operator through the graphical user interface allowing for real-time manipulation of the magnetic resonance imaging inputs and for displaying the magnetic resonance response thereto.

CROSS REFERENCE TO RELATED APPLICATIONS

This Application for Patent claims the benefit of priority from, andhereby incorporates by reference the entire disclosure of U.S.Provisional Application for patent Ser. No. 60/203,326, filed May 11,2000.

BACKGROUND OF THE INVENTION

1. Technical Field of the Invention

The present invention relates to the field of magnetic resonance imaging(MRI) and, in particular, to a system and method for aiding theefficient design of pulse sequences.

2. Description of Related Art

Until the development of MRI and Nuclear Magnetic Resonance (NMR)technology by Dr. Raymond V. Damadian in the 1970's, diagnostic imagingof internal physiology was limited to techniques which provide limitedsoft tissue contrast. For example, as is well understood in the imagingart, computed tomography (CT) techniques depend on tissue density, e.g.,soft tissue compared to bone, and usage of contrast media, e.g., barium,both affecting x-ray attenuation and detection. Although CT, at present,reveals better bone detail, MRI is far superior for most other softtissues, illuminating the internal networks and pathways to physicianswithout the known deleterious effects of x-rays.

Although a full description of how MRI works is not necessary to theunderstanding of the subject matter of the present invention, a briefillustration of the physical principles involved is set forth below. Inshort, MRI is a diagnostic method for providing detailed specimen imagesthrough manipulation of atomic nuclei, specifically hydrogen, within aspecimen tissue. A fundamental property of individual nuclear particlesis that individual particles spin or rotate about their own respectiveaxes. As is understood in physics, a spinning charged particle producesa magnetic moment directed along that particle's axis of rotation. Thesespinning nuclei and their resulting moments are randomly oriented in theabsence of any external magnetic fields. However, by applying a magneticfield, the rotating nuclei essentially align their axes either inparallel or in opposition to the magnetic field. Those nuclei aligned inopposition to the magnetic field have a higher energy than those nucleithat are aligned in parallel with the field. A small majority of nucleiwill be aligned in the lower energy state, i.e., in parallel, thanopposed to the same field, usually only measuring in parts per millionfor the excess. By the addition of energy, e.g., by application of radiofrequency (RF) energy, to these lower energy state excess nuclei, thesenuclei can be transitioned to align themselves antiparallel or inopposition to the magnetic field. As is understood in the art, it isthese few realigned nuclei that ultimately provide the information usedto generate an MRI image.

While the respective nuclei are generally aligned with the appliedmagnetic field, it should be understood that this alignment is notprecisely with a plane parallel to the axis of the magnetic field.Instead, the nuclear moments align at a slight angle from the axis ofthe magnetic field and precess about this axis. This frequency ofprecession, along with the magnetic moment caused by the alignment ofthe nuclei, comprise the phenomenon on which imaging by magneticresonance is based.

The frequency of this atomic or nucleic precession, also referred to asthe Larmor frequency, is a function of the specific nucleus and thestrength of the external magnetic field. The nuclei will absorb energyand induce a signal in adjacent RF receptor coils only at the particle'sLarmor frequency—an event referred to as “resonance.” In other words, byapplying energy to the specimen at the Larmor frequency, the netmagnetic moment of the excess nuclei may be reversed, or deflected, tothe opposite or antiparallel direction by causing these parallel stateparticles to elevate to the higher energy state. The radiofrequencyenergy pulses applied are referred to as “excitation pulses.” Theduration of the RF pulse specifies the duration of the nuclear momentdeflection. When the excitation pulse is removed, the nuclei will thenbegin to lose energy, causing the net magnetic moment to return to itsoriginal, lower energy state orientation, and the energies emittedduring this transmission are used to create the image of the specimen.

Present day MRI devices generally scan only hydrogen atoms. The hydrogenatom is most attractive for scanning since it comprises the largestatomic percentage within the human body and provides the largestmagnetic resonance (MR) signal respective to other elements present inhuman organs. As described hereinabove, every nuclear particle spinsabout its axis and the individual properties of the spin are defined bythe specific nuclear particle in question, e.g., hydrogen, creating amagnetic moment with a defined magnitude and direction. The MagneticResonance (MR) signal itself is a complex function dependent upon theconcentration of the deflected hydrogen atoms, spin-lattice relaxationtime (T1), spin-spin relaxation time (T2), motion within the sample andother factors as is understood in the art.

Another component of the MR signal is, of course, the particular seriesof RF and magnetic field gradient pulses employed in the form of pulsesequences. Varying the pulse sequences can produce considerable imagedifferences, such as T1 emphasis (T1-weighted), T2 emphasis(T2-weighted), proton density emphasis or combinations thereof. Commonsequences include Gradient Echo (GE), Spin Echo (SE), Inversion Recovery(IR), Double Spin Echo, 3-dimensional Gradient Echo (3DGE),3-dimensional Spin Echo (3DSE), Fast Spin Echo (FSE), Partial Saturation(PS) and others. It is understood that these sequences are illustrativeonly and the present invention is in no way limited to application ofonly these specific sequences. Since one sequence image type may notoptimally illustrate an area of consideration, multiple images usingvarying sequences of pulses may be required to fully analyze the area,as is understood in the art.

At present, conventional MRI systems offer fairly primitive interfacesfor the design of the aforementioned pulse sequences. In particular,present MRI systems are ill-suited for sequence designers who must inputand modify customized pulse sequences. Furthermore, this input isgenerally made by coding the sequence in a programming language, e.g.,C, and is further complicated in that the coded sequence format must betailored for each individual machine, thus necessitating that thesequence designer must be skilled in the programming arts along with theMRI technologies or alternatively requiring an MRI sequence designer towork in coordination with a programmer. Consequently, conventionalsystems generally lack real-time communications with the MRI scannersince each sequence must first be coded and compiled prior to beingloaded on the system.

Accordingly, a first object of the present invention is to provide animproved MRI apparatus for more efficient creation and development ofMRI pulse sequences.

It is a second object of the present invention to provide a graphicaluser-interface for performing the mathematical calculations related toMRI pulse sequence design, thereby providing an automatic graphicalresponse of the interface to user manipulation, facilitating interactionbetween the user and the interface.

It is a third object of the present invention to provide a graphicaluser-interface for intermediating between the sequence designer and theMRI hardware such that the designer can directly view the details of theentire pulse sequence but can also access and modify the sequencesdirectly through a mouse or keyboard.

It is a fourth object of the present invention to provide a real-timeinterface, or front-end, between the graphical user-interface and theMRI system hardware that enables real-time communication and interactionbetween the sequence creator and the MRI system hardware.

It is a fifth object of the present invention to provide real-timecommunication and interaction between the sequence creator and the MRIsystem hardware, enabling data acquisition and graphical display of theRF shapes, gradient waveforms and MRI signals received inside themagnetic field and providing analysis of this information in real-time.

It is a sixth object of the present invention to provide a real-timecommunication and interaction between the sequence creator and the MRIsystem hardware, thereby enabling dynamic manipulation of the details ofa MRI pulse sequence accessed through the graphical user-interface.

It is a seventh object of the present invention to provide a real-timecommunication and interaction between the sequence creator and the MRIsystem hardware that enables detection of dynamic deficiencies of theMRI system through feedback information and possible compensation forthe deficiencies through sequence manipulation.

It is an eighth object of the present invention to provide a foundationfor development of automated calibration of imaging sequences of an MRIsystem.

SUMMARY OF THE INVENTION

The present invention is directed to a system, apparatus and method forfacilitating magnetic resonance imaging (MRI) pulse sequence generationand modification and for real-time sequence input modification for usein conjunction with magnetic resonance imaging equipment. A graphicaluser interface is provided through a display coupled to a digitalcomputer operating as the primary control system for a magneticresonance imaging scanner and associated hardware. Through the graphicaluser interface, an operator, either at the site of the MRI unit or at aremote location, may choose or design sequences of radiofrequencypulses, gradient waveforms and other input parameters for the magneticresonance imaging apparatus. Real-time information is also communicatedto the operator through the graphical user interface allowing forreal-time manipulation of the magnetic resonance imaging inputs and fordisplaying the magnetic resonance response thereto.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete understanding of the system, method and apparatus of thepresent invention may be obtained by reference to the following DetailedDescription when taken in conjunction with the accompanying Drawingswherein:

FIG. 1 is a simplified diagram of a magnetic resonance (MRI) imagingsystem upon which the principles of the present invention are performed;

FIG. 2 illustrates an exemplary MRI scan controller interfacing thecontrol system with the MRI hardware on which the present invention canbe applied;

FIG. 3 illustrates an exemplary graphical user interface from which auser can initiate a sequence design according to a preferred embodimentof the present invention;

FIG. 4 illustrates an exemplary settings dialog box for accepting userdefined resolution parameters;

FIG. 5 illustrates an exemplary sequence-type dialog box for allowing auser to define various parameters associated with a given type of pulsesequence;

FIG. 6 illustrates an exemplary sequence-tailor dialog box providingvarious controls for user selection;

FIG. 7 illustrates an exemplary sequence display for displaying varioussequence plots to the user and allowing user interaction therewith;

FIGS. 8A through 8C provide additional illustration of an exemplarysequence display having additional control elements invoked forassisting a user in timing analysis of the various plots;

FIGS. 9A through 9C illustrate various control dialog boxes availablethrough invocation of a shape editor command;

FIGS. 10A, 10B, and 10C illustrate an imaging parameters dialog box fordisplaying and accepting modifications to various imaging parameters;

FIG. 11 illustrates a scan gradient wave option box and displayedparameters;

FIG. 12 is an exemplary graphical representation of a variable windowused in accordance with the Gradient Wave Scan dialog box of FIG. 11;

FIGS. 13A and 13B illustrate plot editing commands available formodifying and design of a pulse sequence;

FIGS. 14A and 14B illustrate an exemplary embodiment of integralcondition calculations according to a preferred embodiment of thepresent invention;

FIGS. 15A and 15B provide further illustration of the automated integralconditioning of the present invention;

FIGS. 16A through 16D provide illustration of acceleration compensationin a slice select (SS) gradient, velocity compensation in signalrecognition (RO) and automatic integral conditioning thereof;

FIG. 17 illustrates a secondary window invoked at real-time interfacinginitiation;

FIGS. 18A and 18B illustrate an exemplary tuning display andillustrative plots displayed therein; and

FIG. 19 illustrates an exemplary scan parameters dialog box according toa preferred embodiment of the present invention.

DETAILED DESCRIPTION OF PRESENTLY PREFERRED EXEMPLARY EMBODIMENTS

The numerous innovative teachings of the present application will bedescribed with particular reference to the presently preferred exemplaryembodiments. However, it should be understood that this class ofembodiments provides only a few examples of the many advantageous usesof the innovative teachings herein. In general, statements made in thespecification of the present application do not necessarily delimit anyof the various claimed inventions. Moreover, some statements may applyto some inventive features but not to others.

As discussed hereinabove, current magnetic resonance (MR) imagingapparatuses may utilize a number of different pulse sequences. Moreparticularly, MR images are obtained by using an appropriate sequence ofspecific RF pulses, signal (echo)-gathering times (TE) and sequencerepetition times (TR). For example, dependent on the desired imageemphasis, e.g., T1, T2, or proton density, specific sequence types canproduce dramatically different imaging results. As discussed, examplesof common pulse sequences include Gradient Echo (GE), Spin Echo (SE),and Inversion Recovery (IR), as well as Double Spin Echo (DSE), 3-DGradient Echo (3DGE), 3-D Spin Echo (3DSE), and Fast Spin Echo (FSE).Again, it is understood that the present invention is not limited by thesequences listed above. The present invention greatly simplifies themanipulation of MR imaging parameters by allowing for more efficientsequence design and parameter tailoring via a digital computer, asdiscussed in more detail hereinbelow. The present invention allows adesigner to generate and modify a variety of sequences quickly andefficiently through a graphical user interface coupled to a digitalcomputer, where the digital computer is itself may be coupled to themagnetic resonance imaging equipment. Additionally, the system of thepresent invention allows for real-time communication with the MR scannerproviding real-time viewing of MRI signals, gradient waveforms and RF(pulse) shapes. Furthermore, sequences can be calibrated automaticallyand dynamically in response to parameter input from the designer.

The present invention may be more readily understood with reference toFIG. 1 in which an exemplary magnetic resonance imaging (MRI) unit 150as implemented in a preferred embodiment of the present invention isgenerally depicted. A specimen aperture 155 is centrally located withinthe bulk of the MRI unit 150 scanning apparatus. Surrounding thespecimen aperture 155 are gradient coils 180, transmitter coils 190 andreceiver coils 195. The gradient coils 180 provide the gradient waveformfor facilitating selective excitation, echo formation and localization,among other purposes, as is understood in the art. Generally, thegradient coils are responsible for generating the gradient field incorresponding axes in mutually orthogonal directions, e.g., designatedaccording to the Cartesian x, y and z coordinates, and thus are drivenindependent from one another. The transmitter coil 190 is responsiblefor delivering the RF pulses into the aperture 155 at the Larmorfrequency for providing excitation of the protons in the specimen, e.g.,a human body. The receiver coil 195 is responsible for acquiring thesignal generated from the excited protons during the proton relaxationperiod, as is understood. Driving these coils and interfacing the MRIunit 150 with a computer 110 is a scan controller 130. The scancontroller 130 is the hardware that provides the real-time data deliveryto and from the various equipment, e.g., digital to analog converters,as described more fully hereinbelow with reference to FIG. 2. An ironyoke 170 completes the circuit by coupling the poles of the magneticmaterial of the plates. It is understood that permanent magnets, as wellas superconducting magnets, may be suitably interchanged for theresistive electromagnet.

Magnetic material provides a primary static, i.e., uniform and constantwith respect to time, magnetic field for surrounding the specimen to beimaged. Gradient fields corresponding to the Cartesian coordinates areused for coding position information with respect to the MRI echoes.Therefore, three separate gradient coils 180 are required, each coilbeing independently driven. A digital computer 110 equipped withstandard input devices, e.g., a keyboard 115, a mouse or pointer device140, and output devices, e.g., a display 120, facilitate the sequencedesigner's interaction with the scan controller 130 and thus the overallMRI unit 150. An MRI pulse sequence containing all the information,e.g., three gradient waveforms, RF pulse shape definitions, signalacquisition timing data, etc., for generating an MRI signal, i.e. anecho, can be designed, modified or stored within computer 110 forapplication to the system according to the present invention.

With reference now to FIG. 2, a more detailed illustration of the scancontroller 130 interfacing between computer 110 and MRI unit 150 isillustrated. Scan controller 130 is in communication with computer 110over data links 202 and 204 for respectively sending and receivingdigital data thereover, although a single bi-directional data link couldbe substituted therefore. Timing of all interactions, includingfrequency and phase settings for the respective transmitter 190 andreceiver coil 195, with MRI unit 150 is coordinated by synthesizers 230integrated within scan controller 130. In a preferred embodiment,synthesizers 230 include two synthesizers which interface with twosynthesizer DACs 231 and 232. The scan controller 130 interfaces withthree gradient DACs 240, 242 and 244, each providing a gradient field inmutually orthogonal planes, as well as two RF shaper DACs 250 and 252.To control and operate an advanced MRI unit as in the preferredembodiment, at least seven DACs are needed to transfer digital inputbetween the scan controller 130 and the MRI unit 150. However, thepreferred embodiment is capable of numerous modifications andrearrangements which would require more or less than seven DACs.Gradient DACs 240, 242 and 244 are supplied with digital gradientinformation describing the x, y and z gradient fields over respectivegradient DAC input lines 241, 243 and 245, as defined by the MRI pulsesequence received by scan controller 130 from computer 110. GradientDACs 240, 242 and 244 then convert the digital gradient data tocorresponding analog gradients which are transmitted to respectivegradient coils 180 over gradient DAC output lines 246, 247 and 248.Thus, gradient DAC 240 is responsible for driving one gradient coil,e.g., gradient coil 180 X of the set of gradient coils 180. Likewise,each of gradient DACs 242 and 244 are responsible for driving acorresponding one of the remaining gradient coils 180, e.g., respectivegradient coils 180 Y and 180 Z.

RF shaper DACs 250 and 252 are responsible for converting the RF shapedata, received over output lines 251 and 253, from the digital domain asdefined in the MRI pulse sequence received by the scan controller 130from computer 110, and modulating the representative RF shapesaccordingly. The RF shapes are received and modulated by transmittercoil 190, generally at the Larmor frequency, to the subject specimenbeing analyzed in aperture 155. The frequency and phase of thesemodulations are controlled by synthesizers 230 over control lines 260and 261. The echo resulting from the applied gradient waveforms and RFpulses is acquired by the receiver coil 195 during the relaxationperiods and accordingly transmitted to the scan controller 130. Properacquisition of the echo is facilitated by frequency and phase settingsapplied to the receiver channel by synthesizers 230. These frequency andphase settings are supplied to the scan controller by the MRI pulsesequence data received from computer 110. Thus, the MRI pulse sequenceprovided by computer 110, under command of an operator thereof, directsthe operations for echo generation and acquisition.

Digital computer 110 includes a processor, e.g., a microprocessor fromthe family of Pentium™ processors manufactured by the Intel™ corporationfor directing and performing operations and receiving and executinginput from a user, e.g., from the keyboard 115 or pointer device 140.Digital computer 110 also contains a bank of random access memory (RAM)for storing and executing commands therefrom, and a long-term storagemedia, e.g., magnetic disk, for storing executable instructions that areretrievable and loadable into RAM. In a preferred embodiment, digitalcomputer 110 has a Microsoft Windows™ operating system for coordinatingand executing instructions and programs, coordinating communications toperipheral hardware, scheduling tasks and allocating hardware. Thepresent invention preferably includes a Windows executable programstored in long-term storage media and executable from RAM, althoughother platforms are not precluded.

The present invention allows for efficient creation and customization ofgeneric pulse sequences through a primary design interface 300, i.e., agraphical user interface presented in the form of a window 305,presented on display 120 and generally depicted in FIG. 3. The designinterface consists of a number of user selectable menu editor items,e.g., New Sequence 310, Sequence Tailor 320, and Delta Size 330, as wellas the common Windows™ menu editor items, e.g., File 340, Edit 350 andView 360, all contained within the mainframe window 305. Various toolbareditor items, e.g., Open File 370 and Save 380, may be located below themenu editor items. Selection of a given menu choice initiates generationof a drop-down box, e.g., drop-down box 390 resulting from userselection of the new sequence menu editor item 310. Each of the menueditor items will generally have a drop-down box associated therewith,each of which generally provide the user with additional selectionsassociated with the selected menu item. A specific dialog box may beactivated by selection of a drop-down box item. For example, a NulSequence drop-down box item 396, when selected, activates a specificdialog box (not shown) that allows the user to create a sequence fromscratch. A Fast Spin Echo (FSE) drop-down box item 392, when selected,activates a dialog box that allows the user to edit a Fast Spin Echosequence; likewise a Fast Gradient Echo (FGE) drop down box item 394,when selected, activates a dialog box that allows the user to edit aFast Gradient Echo sequence. The user has unrestricted freedom to builda sequence from existing types, while providing the advantages of copy,modification, and other functions provided by the user interface.

In FIG. 4 is illustrated an exemplary Settings dialog box 400 displayedwithin the mainframe window 410 for accepting resolution data for a newsequence. Settings dialog box 400 preferably is activated by selectionof any option within drop-down menu 390. The Setting dialog box 400preferably includes an RF resolution box 402, a gradient resolution box404, and a graphic resolution box 406. A user may enter a desirednumerical value, as depicted in this illustrative example, or accept thesystem defaults, e.g., 4 and 16 microseconds for the respective RF andgradient settings. The graphic resolution box 406 allows the user tohave an option between speed and clarity of the graphic drawing. Theuser may choose the default graphic resolution, or may opt to enter ahigher or lower resolution. When entering a higher resolution, screenrepainting requires more time than the default resolution. The lack ofspeed becomes an issue when performing a sequence with long trainechoes, such as FSE and EPI with 127 or 256 echoes. The displayedsettings are accepted by selecting the OK button 408.

A sequence parameters dialog box 500, as illustrated in FIG. 5, isdisplayed in the event that the resolution settings are accepted in thepreviously displayed Setting dialog box 400. The sequence parametersdialog box 500 displays various user definable attributes or parametersassociated with a selected generic pulse sequence. As illustrated inFIG. 5, the sequence parameters dialog box 500 preferably includesdefault values, such as a sequence name box 502 and a TE field box 504indicating 85 ms, which are prestored with the associated genericwaveform characteristics within computer 110. A number of attributefields are also included in the sequence parameters dialog box 500, agroup of gradient motion compensation field values 506, various RF pulsecharacteristics field values 508, and data acquisition field values 510.A user designing a sequence can, of course, accept the default values byselecting the confirmation command, e.g., clicking on an OK button.Doing so results in a logical association of the depicted parameterswith respect to the selected generic pulse sequence. The user also hasthe option of canceling the sequence design by selecting a cancelbutton. Advantageously, the user also has the option to manually modifythe displayed sequence or acquisition parameters by manually entering adesired value in any one of the sequence parameter boxes.

FIG. 6 illustrates a sequence tailor dialog box 600 that is preferablydisplayed after acceptance of the sequence parameters from sequenceparameters dialog box 500. The sequence tailor dialog box 600 comprisesfour main control features in which the user may interact: controlssection 602, shape editor 604, block editor 606, and time scaling 608.Each of these sections have at least one object through which the usermay supply input. These objects may include the calibration check box610, delta on check box 612, the update lock checkbox 614, and the shapeeditor radio button 616, or any other graphical object useful forobtaining user input.

The various controls activated through the sequence tailor dialog box600 are preferably available for user interaction therewith during whichthe current sequence design is displayed to the user according to anexemplary sequence display 700 as illustrated in FIG. 7. The sequencedisplayed corresponds to a sequence selection made as describedhereinabove. The sequence name as entered in the sequence name field502, is provided on the sequence display 700 title bar 702. Thegraphical display of a sequence within the sequence display 700 ispreferably divided into four general sections. The topmost section ofsequence display 700 provides a graphical display of the RFcharacteristics of the sequence as currently designed and is designatedas the RF display 704.

A second portion 706 of the sequence display 700 of FIG. 7, displays aslice select (SS) gradient graph 708, representing the gradient used fora particular slice selective excitation. For example, if an axial(transverse) specimen image is desired, the slice select gradient 708would be termed “Gz”, meaning that the external field is aligned withthe z-axis. It is understood that slice select gradient may be taken onany of the Cartesian axes, such as Gx or Gy, depending on the desiredslice orientation.

The third portion, RO section 710, of the sequence display 700 of FIG. 7represents the dephasing or signal acquisition (RO) graph 712. The ROsection 710 essentially provides signal location information for a givenecho and is typically calculated by a fast Fourier transform algorithm.Final image generation may be performed locally by the digital computer110 or may be offloaded to high speed numerically intensive systems.

The lowermost portion 714 of the sequence display depicts the phaseencoding (PE) graph 716.

Four horizontal lines 718, 720, 722, and 724 respectively indicate thezero-amplitude of the respective RF section 704, SS section 706, ROsection 710, and PE section 714. The time coordinate commonly sharedamong each of the plots is represented according to standard conventionalong the horizontal and originating from the leftmost side of thesequence display 700. Preferably, the four sections of the sequencedisplay 700 are automatically scaled according to calculated maximum andminimum amplitudes of the waveforms displayed therein. Thesecalculations are performed upon confirmation of the original setting byselection of the OK button in settings dialog box 400. The conventionspreferably defining these scaling calculations are:

RF 704—a maximum positive amplitude of a RF shape is of 100 scalingunits;

SS 706—the gradient plateau corresponding to the slice selective RFpulse is of 100 scaling units;

RO 710—the gradient plateau corresponding to the data acquisition windowis of 100 scaling units; and

PE 714—the absolute maximum amplitude among all the PE plateaus, whichare stepped during the scan, is of 100 scaling units.

Detailed information regarding a particular point of a given plot may beobtained through user interaction with the user interface 305 preferablythrough directions of the mouse 140. An exemplary tool tip box 726 isdisplayed when the mouse pointer is positioned over a given point, ornode of a displayed plot. As illustrated, the tool tip box 726 providesdetailed numerical data representative of the subject node. Theexemplary tool tip box 726 indicates that the selected node is the tenthnode (starting from node zero) along the RO gradient and represents atiming of 43.52 milliseconds along the plot. Furthermore, the ROamplitude is also provided (0.000) as well as the respective timedifferences between the previous node (1.024 ms) and the next node(2.512 ms) of the associated plot. Data related to the other plots canbe obtained by simply directing the mouse pointer to a displayed node onany of the displayed plots.

As previously mentioned with respect to FIG. 6, sequence tailor dialogbox 600 is provided with various controls such as Block Editor Single618 and Global 620 radio buttons and time scaling Xscaling 622 andNormalize 624 radio buttons, and preferably is displayed concurrentlywith user interface 305.

These various controls can be utilized for further plot enhancements, asillustrated in FIGS. 8A–8C. It should be understood to one skilled inthe art that the aforementioned Xscaling is for the purpose of insertingnew waveforms at the beginning, middle, or end of an existing waveform.Various vertical lines 802, 804, 806, 808, 810, 812, 814, 816, and 818are displayed in response to user selection of the Xscaling radio button622. These vertical lines pass through each of the displayed plots andassist the user in analysis of the timing relations among the RF pulse,data acquisition and gradient waveforms. An example of such timingrelation is indicated in FIG. 8B. The duration of the slice plateaushould be approximately equal to or slightly larger than thecorresponding RF shape duration. In this illustrative example, a usercan quickly make an assessment of this relation by selecting theXscaling radio button 622 and noting the relation of the RF shapeduration spanning vertical lines 802 to 806. In this instance, the SSplateau duration is slightly larger than the RF pulse duration,indicating a proper relationship. Various other timing relations caneasily be confirmed, such as verification that a PE gradient occurs onlyduring periods with no RF pulse or data acquisition, by viewing theexemplary plots as graphically displayed in the preferred user interface305. FIG. 8 c is illustrative of the vertical scaling dependency on thesubject sequence.

Further controls are provided by selection of the shape editor radiobutton 616 in the sequence tailor dialog box 600 as depicted in FIG. 6.When this control is selected, a shape editor dialog box 900 isdisplayed as illustrated in FIG. 9A. This dialog box allows the user toeither modify the RF shape parameters by selection of the modifyparameters button 902, or modify the RF shape itself by selection of theselect types button 904.

Selection of the modify parameters button 902 generates a shapemodification dialog box 910, as illustrated in FIG. 9B. The shapemodification dialog box 910 displays the current settings of theparameters of the selected RF shape. A user can modify the parametersassociated with the current RF shape by changing the parameters to thedesired value, entered by the user, of any of the displayed parameterssuch as amplitude of sinc 912, cycles of sinc 914, exponential of sinc916, amplitude of cosine 918, cycles of cosine 920, exponential ofcosine 922 and asymmetric factor 924. Upon acceptance of the modifiedparameters, the RF plot, SS plot 708, RO plot 712, and the PE plot 716of FIG. 7 are redrawn for display accordingly.

If the user selects the select types button 904 in the shape editordialog box 900, as shown in FIG. 9A, a shape selection dialog box 950 isdisplayed, as shown in FIG. 9C. A shape drop down box 952 within theshape selection dialog base 950 displays the current selected shape. Byselecting the drop down arrow 954, the shape drop down box 952 expandsto provide the user with a selection of available RF shapes, such asGausian, Gasico, Hermite, etc. Selection of a RF shape different thanthe current RF shape will result in the RF plot, SS plot 708, RO plot712, and the PE plot 716, being redrawn for display upon return to userinterface 305. Preferably, prestored numerical shape files may beaccessed through selection of the shapes available via button 956.

When a sequence is created and modified, it can be saved with theoriginal user-assigned name by selection of the Save item (not shown)provided by selection of the File menu editor item 340, as illustratedand described in connection with FIG. 3. Alternatively, a new name canbe assigned by choosing the Save As item from the File menu editor item340. In either case, the saved sequence is digitally stored in,preferably, a plurality of files, each of which defines a particularaspect of the saved sequence. These files are preferably stored within astorage device of computer 110, as illustrated in FIG. 1. In a preferredembodiment, there are eleven files created and saved when a user choosesto save a given sequence. These files include seven binary files forinput to the various DACs described hereinabove, as well as adocumentation file, e.g., a MS Word document (.doc), a source file suchas a C++ file (.cpp) and a graphical file for sequence plotting such asa .gwa file. The seven binary files for directing the DAC operations canbe combined into a single file to reduce the number of stored files. Thedocumentation file preferably provides all the numerical valuesdescribing the sequence including a report on various critical valuesrelated to the sequence and the overall system, e.g., maximum risingtime and electrical currents of the associated gradient.

After a sequence is designed and stored, an MRI scan is available to beperformed. This is initiated through selection of the ScanSettings menueditor item 1000, as illustrated in FIG. 10A. The ScanSettings menueditor item 1000 is included in the main menu of the primary designinterface 300 but only the ScanSettings 1000 menu editor item and itsassociated drop down menus 1002, 1020, and 1040, and a Setting ComboImaging Parameters dialog box 1050A are illustrated in FIG. 10A. Whenthe ScanSettings menu editor item 1000 is selected, the ScanSettingsdrop down box 1002 is displayed and provides the user with a selectionof scan parameters to perform a scan.

In the illustrative example, the MRI Scans option 1004 is selected andcauses the MRI scan type drop down menu 1020 to be displayed. Eightdifferent types of scans are illustratively available for selection,e.g., 2D-Scan 1022, 2D-Variable TR Scan 1024, 3D-scan 1026, FSE 2D-scan1028, FSE 3D-scan 1030, Multiple 2D-Scans 1032, Multiple 3D-Scans 1034,and Combo Scan 1036. It should be understood, however, that the numberand type of available scans is not limited to the illustrative examplesdepicted.

If a scan type selected does not have an associated sequence typealready loaded as aforedescribed, an error message is generated anddisplayed to the user indicating the absence of the desired sequencetype. Additionally, the error message is generated to remind the userthat the desired scan did not match the type of sequence. A simpleexample of the image parameter setting is illustrated in FIG. 10C. ASetting Imaging Parameters dialog box 1080, as illustrated in FIG. 10C,is displayed upon selection of MRI Scans type having an associatedsequence type already currently loaded. The Setting Imaging Parametersdialog box 1080 also displays numerous other parameters which are listedabove with reference to FIG. 10A. The default settings are displayedconsistent with the sequence already displayed in the user interface305. In the illustrative example of FIG. 10A, the Combo Scan option 1036is selected, which activates the display of a combination type drop downmenu 1040. The user may want to perform the combo scan 1036 whenperforming a coronary MRA or MRI guided surgery. In the preferredembodiment, a user may choose between a StaticCombo scan 1042 and aDynamicCombo scan 1044. When the StaticCombo scan 1042 is selected, asillustrated in FIG. 10A, the Setting Combo Imaging Parameters dialog box1050A is displayed. In this illustrative example, the first sequencedenoted in a first sequence name box 1052 is used for an extremely factdetective scan, whereas the second sequence denoted in a second sequencename box 1054 is used for actual imaging. The name of the combination ofsequences is preferably provided in a sequence name box 1056. A defaultfirst sequence echo gathering time parameter 1058, and a default secondsequence echo gathering time parameter 1060 are also displayed. Variousother imaging parameters are preferably provided, e.g., number of slices1062, slice thickness 1064, sequence repetitions, number of phaseencoding levels 1066, Discrete Fourier Transform (DFF) size 1068, and180 RF polarity flipping. These displayed parameters are exemplary onlyand can be tailored according to the software designer's preference. Thenumerical values associated with the various displayed parameters aremodifiable by the user by simply entering different values from thedefaults and accepting the entered values by selection of the OK button.Upon acceptance of the default values, or values substituted therefor,two files (.va and .exam) are preferably generated and savedaccordingly. These files provide information for proper setting ofsequences, scan and image reconstruction required for the variousimaging components.

A Setting Combo Imaging Parameters dialog box 1050B, as illustrated inFIG. 10B, is displayed when the user selects to perform a DynamicComboscan 1044. The trigger sequence used is denoted in a trigger sequencename box 1070, and the imaging sequence used is denoted in a imagingsequence name box 1072. Various other parameters, such as those listedabove with reference to FIG. 10A, are also displayed in the SettingCombo Imaging Parameters dialog box 1050B.

FIG. 11 illustrates a preferred embodiment of the present invention whena Scan A Gradient Wave option 1006 is selected from the ScanSettingsmenu editor item 1000. The ScanSettings drop down box 1002 and the MRIScans option 1004, as described hereinabove in connection with FIG. 10Aare shown for illustration. Upon selection of the Scan a Gradient Waveoption 1006, an interference dialog box 1100 is displayed. Selecting theOK button on the interference dialog box 1100 causes a Setting ofGradient Wave Scan dialog box 1120 to be displayed. The Setting ofGradient Wave Scan dialog box 1120 allows a user to enter a particularwindow location and size with which to compare the input and outputretrieved from the magnetic field. The user may enter values in avariety of parameter boxes, e.g. a sequence name box 1122, a sequencerepetition times box 1124, a number of data acquisition box 1126, and asample interval box 1128.

FIG. 12 illustrates an exemplary graphical representation of a variablewindow 1200 which can be selected in the Setting of Gradient Wave Scandialog box 1120 in FIG. 11. In this example, the user selected the SSgradient with a sample interval 1128 of 16 microseconds. One skilled inthe art will recognize that the settings pertaining to FIG. 12 are forillustrative purposes only. The user may select a number of othergradients to compare, and may select a variety of other sampleintervals.

The present invention also allows for ‘cut’ 1302, ‘copy’ 1304, ‘paste’1306, ‘invert’ 1308, and ‘flip’ 1310 procedures to further expeditesequence design and modification as may be better understood withreference to FIGS. 13A and 13B. FIG. 13A simply illustrates the user'saccess to the abovementioned procedures by selection of the Edit menuitem 350. FIG. 13B provides an illustrative example of the various plotsassociated with a given sequence and an exemplary illustration of a copyprocedure to expedite a sequence modification. On the PE plot 1320, awaveform has been selected for copying as indicated by a shaded selectedarea 1322. Generally, selecting an area is accomplished through clickingand dragging the desired area 1322 with the pointer device 140. Thecontents of the selected area 1322 are next copied to the computer 110memory by choosing the Edit menu item 350 followed by the Copy 1304command from the Edit drop down menu 1312 of FIG. 13A. Once the contentsare copied to the computer 110 memory, the user may then select a pointin one of the displayed plots, for example, point 1324 at which to pastethe copied waveform. As illustrated, the waveform pasted at point 1324is an inversion of the original copied waveform. This is accomplished byselection of the invert command 1308 from the Edit menu item 350 afterthe paste procedure. Thus, by this method, an FSE sequence, for example,can be designed from duplicating the parts of a generic SE sequence. Itshould be noted that, as illustrated, it is not necessary that awaveform be copied from the same plot.

An important innovative aspect of the present invention is thecapability for real-time communication between the MRI scan controller130 and the scanning hardware, e.g., MRI unit 150, allowing forimmediate design modifications and corresponding visual feedback. In thecurrent preferred embodiment, seven binary files corresponding to thegraphic waveforms on the screen have been generated. The seven binaryfiles correspond to the preferred seven DACs, the gradient DACs 240,242, and 244, the RF shaper DACs 250 and 252, and the synthesizer DACs231 and 232 interfacing the MRI control system, the computer 110, withthe MRI scanning hardware. Thus, two binary files exist forsynthesizers, two for shapers, and three for the gradients. Utilizingseven binary files for real-time communication between the MRI hardwareand control system is only a preferred embodiment of the presentinvention. As previously mentioned, the system and method are not,however, limited to such an arrangement but can be extended or reducedto any number of DACs depending upon the actual system on which thepresent invention is applied.

In order to provide real-time design and feedback, an accurate timeframe reference is needed to be established. Since all of the digitalelectronic devices in the overall MRI system accept integer valuesgenerally limited by the bit-size of the associated DAC, small errorscan accumulate during operation due to round-off of input data fromvarious assignments and calculations when the sequence is built. Thismay sometimes lead to serious consequences for proper realization of aMRI pulse sequence. Thus, it is particularly important for a real-timeinteractive system, as described herein, to provide verification andround-off correction procedures between the displayed graphics and allthe DACs to ensure time alignment throughout the entire sequence designprocess. The timing error due to roundoff depends on the settings of thetime-resolution, generally on the order of microseconds, in thehardware. However, the accuracy of all calculations and roundoffsubroutines in the user interface is preferably on the order of a singlenanosecond. Every piecewise segment of the waveform is rounded off to bean integer-multiple of the three different time units, i.e., the unitfor the RF pulses, the unit for the gradient waveforms and the unit forthe sampling rate. Potential conflicts among the three time coordinatesare resolved prior to the integral conditions, i.e. the gradientwaveform specifications required to produce an echo, being applied. In apreferred embodiment of the present invention, satisfaction of theintegral conditions are performed automatically by the underlyingalgorithm. This occurs not only at the initial sequence design stage,but also during gradient waveform modification, for example. Thus, thepresent invention provides a dynamic response to the user's adjustmentby dynamic calculation and adjustment for satisfaction of the requisiteintegral conditions, e.g., by input via mouse 140 such as dragging ofthe gradient for modification thereto or by delta tuning.

Satisfaction of the integral conditions, as had by the presentinvention, may better be understood with reference to FIGS. 14A and 14B.To obtain the largest echo amplitude, both the SS and RO gradients mustsatisfy the corresponding integral conditions. For the SS integralcondition, the time integrated area of SS area 1400 must be equivalentto the time integrated area of SS area 1402. This is because the protonsexcited by the RF pulse 1404, dephase during the time period of SS area1400 and subsequently rephase during the span of time corresponding tothe SS area 1402. Similarly, the time integrated area of RO area 1406must be equivalent to the RO area 1408.

To refocus the spins that are in motion, higher order integralconditions are required. This scenario is illustrated in FIG. 14B. Inthis illustration, a gradient sequence that has both stationary spinsand spins moving in constant velocities are refocused at the time of theecho center, i.e. the signal components contributed by the spins inconstant velocities are included in the image instead of, as would occurotherwise, the motion artifacts. Calculation of the integral conditionfor a particular sequence comprises the solution of a set ofsimultaneous integral equations depending on the order of compensation.As noted above, these integral conditions are calculated, and thesequences are modified accordingly, both at the initial sequence designand dynamically as modifications are being made to a sequence.

In FIG. 15A is illustrated a gradient sequence with velocity motioncompensation for both the SS and RO gradients. The default timingsettings of SS nodes 1500 and 1502 and RO nodes 1504 and 1506, are alsoillustrated. For the SS gradient, the time and amplitude of node 1500are initially 7.232 ms and −116.689, respectively, while the time andamplitude of node 1502 are initially 8.256 ms and 58.358, respectively.The SS gradient was then modified by dragging node 1502 to a timingposition of 10.000 ms, denoted node 1502B in FIG. 15B. In order tosatisfy the integral condition such that the resulting echo will beformed at a substantially identical position as an echo resulting in thenon-modified SS gradient as illustrated in FIG. 15A, the SS gradientmust be modified. This modification is apparent in FIG. 15B by theamplitudes of nodes 1500B and 1110B automatically adjusting to −95.313and 90.017, respectively so that the integral conditions are stillsatisfied. Similarly, in FIGS. 15A and 15B, node 1504 of the RO gradienthas been dragged from an initial time of 6.720 ms to 5.536 ms. Theimmediate response displayed in the user interface is an adjustment ofamplitude of RO node 1504 from 165.123 to 215.023 (indicated as node1504B) and an adjustment of RO node 1506 amplitude of −279.913 to−241.386 (indicated as node 1506B).

In FIGS. 16A through 16D is illustrated a spin echo sequence exampledepicting motion compensation of the SS gradient for acceleration and ROfor velocity compensation.

As described, the present invention is generally composed of twoportions: the graphical user-interface and the real-time MRI interface,or front-end. The real-time MRI interface allows communication betweenthe graphical user-interface, and thereby the user, with the systemhardware. The primary task of the front-end is to translate the output,e.g., the seven binary files, of the graphical user-interface into thedata format required for input to the hardware and MRI controller and toretrieve the digitized signal from the system for either display inproper graphical form or delivery back to the user-interface forinteraction purposes. Three types of analyzers for handling the threedifferent kinds of signals, i.e. MRI signals, gradient waveforms and RFshapes, received from inside the aperture 155 are required. All threeanalyzers require the real-time feedback and capabilities for a fullyreal-time and interactive MRI process.

Accordingly, a second window (in addition to the aforedescribed primaryuser interface 300 window, and the various manifestations thereof) iscreated when the real-time interface is invoked and is illustrated inFIG. 17.

Second window 1700 contains various menu editor items, e.g., File 1702,Scan Control 1704, Seq Tuning 1706, Tuning Tools 1708 and Scan 1710.When a sequence is created along with the corresponding exam and .vafiles, as described hereinabove, the sequence can be selected by theoptions available (not shown) through the File menu editor item 1702. Inorder to generate and receive the MRI signal, several system parametershave to be tuned properly for the loaded sequence. These parametersinclude, for example, the settings of the central frequency of themagnet 170, the power gain of the RF amplifier, the gain of thereceiver, etc. Tuning of these parameters is performed through a scancontrol dialog box which is invoked by selection of the Scan Controlmenu editor item 1704. The scan control dialog box preferably hasnumerous edit-boxes and selection buttons corresponding to theaforementioned parameters settings. Graphical displays of the signalintensity, spectrum and phase of the MRI echo are also preferablyprovided in subframes for easy user viewing.

Once these parameters are tuned, calibration of the sequence may beinitiated by user selection of the Seq Tuning menu editor item 1706which preferably generates a sequence tuning dialog box 1800, includingfour control frames 1802, 1804, 1806, and 1808, for graphical display,as illustrated in FIG. 18A. Numerous controls are provided and aregenerally divided into a control menu section 1810 and control modesection 1812. Various radio buttons under the control menu section 1810provide selection options for specific signals, e.g., input/output fromthe scanner, real and imaginary parts, and amplitude and phase of theMRI echo to be displayed in the upper and lower frames. The control modesection 1812 provides control to the user of, for example, sequencerepetition times, toggling of each of the gradients, selection of thewarp level of the PE gradient, etc.

In FIG. 18B is illustrated an exemplary artificial harmonic signal asmay be displayed in frames 1802, 1804, 1806 and 1808 of the sequencetuning dialog box 1800, and the control menu section 1810. The real andimaginary part of the artificial harmonic are respectively plotted inframes 1802 and 1806 while the amplitude and phase of the echo arerespectively displayed in frames 1804 and 1808. In addition to the MRIechoes, gradient waveforms and RF shapes could also be displayed in thesequence tuning dialog box 1800 frames.

A scan parameters dialog box 1900, as illustrated in FIG. 19, isgenerated by user selection of the scan menu editor item 1710, locatedin FIG. 17, for performing a phantom scan as part of the calibrationprocess. Numerous scan parameters are displayed therein, e.g., TE 1902,number of slices 1904, TR 1906, NEX 1908, levels 1910, ETL 1912, andslice plane 1914. Some values are modifiable by the user while staticvalues are shaded so that the user can view, but not modify, theparameters. Selection of the scan button 1916 will initiate a scan,resulting in image reconstruction and display for user analysis.

Preferably, there will be two modes of communication between thegraphical user-interface and the front-end. A manual load is availableany time a sequence is selected via the procedure described withreference to the second window 1700 of FIG. 17. The sequence will berepeatedly transmitted to the MRI hardware and executed by the MRIscanner. Returning signals are accordingly displayed on sub-windows, orframes, in the Sequence Tuning dialog box 1800 of FIG. 18. Accordingly,in this mode, the loaded sequence that is repeatedly sent to the MRIhardware remains constant during the scan, i.e. the user is unable tomodify the sequence once it is loaded and running, and thus theaforedescribed techniques for sequence modification are unavailable inthis mode. However, changes made to the sequence can be loaded throughthe reload feature in the editor sequence tuning, as shown in FIG. 17,particularly the Sequence Tuning menu editor item 1706.

A second mode of communication between the graphical user-interface andthe front-end is referred to as auto load and is initiated as soon asthe calibration check box 610 of the sequence tailor dialog box 600 isselected. Thereafter, any change of the sequence through the varioussequence modification techniques are provided for the graphicaluser-interface and automatically reloaded and transmitted to thehardware. These resulting signals are immediately retrieved therebyproviding the user with a real-time display of the various effects ofthe user modifications.

Since the desired sequence often becomes distorted inside the aperture155, the auto-load mode is particularly suitable for dynamic correctionof the gradient waveforms. For instance, the phase information of an MRIecho may be calculated and provided to the graphical user-interfacethrough the front-end. This information may be used to reset thereference frequency and phase of the sequence. Such an automatediterative procedure may be used for phase adjustment and alignment ofthe MRI echoes as well.

Furthermore, initiation of the auto-load mode had by selection of thecalibration check box 506 of the sequence tailor dialog box 600preferably terminates the aforedescribed automatic integral conditioningthereby providing more freedom for sequence manipulation. Concurrently,all related restrictions for modification are terminated.

Although preferred embodiments of the method and apparatus of thepresent invention have been illustrated in the accompanying Drawings anddescribed in the foregoing Detailed Description, it will be understoodthat the invention is not limited to the embodiment disclosed, but iscapable of numerous rearrangements, modifications and substitutionswithout departing from the spirit and scope of the invention as setforth and defined by the following claims.

1. A user interface operable to create, on a display device, a windowdisplaying a plurality of menu editor items for user selection, saidmenu editor items comprising: a sequence editor item that creates an RFpulse sequence from at least one value; and a sequence tailor editoritem configured for user interaction with a graphical representation ofa selected pulse sequence, wherein during said user interaction, theselected pulse sequence is graphically displayed to the user, said userinteraction including dynamic, non-standard and on-the-fly manipulationof, and modification to, said graphical representation of said selectedpulse sequence that is currently undergoing user interaction with realtime visual feedback of the interaction on the manipulated pulsesequence to the user, and wherein said menu editor items furthercomprise an MRI scan setting menu editor item configured for initiationof a magnetic resonance imaging scan.
 2. The user interface inaccordance with claim 1, wherein said sequence tailor editor item isactivated in response to user selection.
 3. The user interface inaccordance with claim 1, wherein user selection of said sequence editoritem activates a display of at least one sequence parameter operative increating said pulse sequence, said at least one sequence parameter beingoperable to accept a default value.
 4. The user interface in accordancewith claim 3, wherein said at least one sequence parameter is operableto accept a user entered value.
 5. The user interface in accordance withclaim 3, wherein said at least one sequence parameter is selected fromthe group consisting of: a gradient resolution parameter, a radiofrequency pulse resolution parameter, an echo gathering time parameter,a sequence name parameter, at least one gradient motion compensationparameter, at least one radio frequency pulse characteristic parameter,and at least one data acquisition parameter.
 6. The user interface inaccordance with claim 3, wherein acceptance, by the user interface, ofthe at least one sequence parameter activates said sequence tailoreditor item.
 7. The user interface in accordance with claim 1, whereinactivation of said sequence tailor editor item activates display of saidpulse sequence and at least one control feature.
 8. The user interfacein accordance with claim 7, wherein said at least one control featurecomprises at least one of a control section, a shape editor, a blockeditor, and a time scaler.
 9. The user interface in accordance withclaim 8, wherein said shape editor, when activated, is operable tomodify at least one radio frequency pulse characteristic parameter andthe radio frequency pulse shape associated with said selected pulsesequence which is displayed to the user.
 10. The user interface inaccordance with claim 8, wherein said time scaler, when activated,displays at least one vertical line through the graphically displayedselected pulse sequence in order to assist the user in analysis oftiming relationships of the pulse sequence.
 11. The user interface inaccordance with claim 1, wherein said graphical representation withinsaid window on said display device is divided into a plurality ofportions.
 12. The user interface in accordance with claim 11, whereinsaid plurality of portions comprises at least one of a radio frequencypulse characteristics graph, a slice select gradient graph, a signalacquisition graph, and a phase encoding graph.
 13. The user interface inaccordance with claim 1, wherein selection of said MRI scan setting menueditor item displays at least one type of MRI scan to perform.
 14. Theuser interface in accordance with claim 13, wherein said at least onetype of MRI scan comprises at least one MRI scan selected from the groupconsisting of: a two dimensional scan, a combination scan, a threedimensional scan, a three dimensional combination scan, a twodimensional fast spin echo scan, and combinations thereof.
 15. The userinterface in accordance with claim 13, wherein said type of MRI scan,when activated, displays at least one setting of an imaging parameter,said setting of the imaging parameter being operable to accept at leastone default value.
 16. The user interface in accordance with claim 15,wherein said at least one setting of an imaging parameter is operable toaccept at least one user-entered value.
 17. The user interface inaccordance with claim 15, wherein said at least one setting of animaging parameter is selected from the group consisting of: a number ofslices parameter, a slice thickness parameter, a sequence repetitionparameter, a number of phase encoding levels parameter, a discreteFourier transform size parameter, a polarity flipping parameter, andcombinations thereof.
 18. A method for creation and customization ofpulse sequences, said method comprising the steps of: creating a windowon a display device, said window displaying a plurality of menu editoritems for user selection; displaying a sequence editor item operative increating an RF pulse sequence from at least one of user-entered valuesand default values; displaying a sequence tailor editor item in order toassist user interaction with a graphical representation of a selectedpulse sequence; and displaying, graphically, said pulse sequence to theuser, said user interaction including dynamic, non-standard andon-the-fly manipulation of, and modification to, said graphicalrepresentation of said selected pulse sequence that is currentlyundergoing user interaction with real time visual feedback of theinteraction on the manipulated pulse sequence to the user, and whereinsaid method further comprising the steps of: initiating a magneticresonance imaging scan by activating a scan setting menu editor itemwithin said window on said display device; and displaying at least onesetting of an imaging parameter.
 19. The method in accordance with claim18, wherein said creating step further comprises the step of: displayinga scan setting menu editor item configured for initiation of a magneticresonance imaging scan.
 20. The method in accordance with claim 19,wherein, upon initiation of said magnetic resonance imaging scan, saidmethod further comprises the step of: initiating at least one of a twodimensional scan, a two dimensional combination scan, a threedimensional scan, a three dimensional combination scan, and a twodimensional fast spin echo scan.
 21. The method in accordance with claim18, further comprising the step of: dividing said graphicalrepresentation within said window on said display device into aplurality of portions.
 22. The method in accordance with claim 21,wherein said step of dividing further comprises the step of dividingsaid graphical representation into at least one of a radio frequencypulse characteristics graph, a slice select gradient graph, a signalacquisition graph, and a phase encoding graph.
 23. The method inaccordance with claim 18, said method further comprising the steps of:displaying, in response to selection of said sequence editor item, atleast one sequence parameter that creates said pulse sequence; andaccepting, by said at least one sequence parameter, at least one of saiddefault values.
 24. The method in accordance with claim 23, wherein saidstep of accepting further comprises the step of: accepting, by said atleast one sequence parameter, at least one of said user-entered values.25. The method in accordance with claim 24, wherein said step ofdisplaying said at least one sequence parameter further comprises thestep of: displaying at least one additional parameter, said additionalparameter selected from the group consisting of: a gradient resolutionparameter, a radio frequency pulse resolution parameter, an echogathering time parameter, a sequence name parameter, a plurality ofgradient motion compensation parameters, a plurality of radio frequencypulse parameters, and a plurality of data acquisition parameters. 26.The method in accordance with claim 24, said method further comprisingthe step of: activating said sequence tailor editor item by at least oneof user selection and a response to said step of accepting of said atleast one sequence parameter by a user interface.
 27. The method inaccordance with claim 26, said method further comprising the step of:displaying the selected one of said pulse sequences and at least onecontrol feature for at least one of plot modification and plotenhancement.
 28. The method in accordance with claim 27, wherein saidstep of displaying further comprises the step of: displaying at leastone of a control section, a shape editor, a block editor, and a timescaler.
 29. The method in accordance with claim 28, wherein said step ofdisplaying at least one of a control section, a shape editor, a blockeditor, and a time scaler further comprises the steps of: activatingsaid shape editor; and modifying at least one of the radio frequencypulse characteristic parameters and the radio frequency pulse shapeassociated with said pulse sequence.
 30. The method in accordance withclaim 28, wherein said step of displaying at least one of a controlsection, a shape editor, a block editor, and a time scaler furthercomprises the steps of: activating said time scaler; and displaying atleast one vertical line through the graphically displayed pulse sequencein order to assist the user in analysis of timing relations of the pulsesequence.
 31. The method in accordance with claim 28, wherein said stepof displaying further comprises the step of: displaying at least one ofa number of slices parameter, a slice thickness parameter, a sequencerepetition parameter, a number of phase encoding levels parameter, adiscrete Fourier transform size parameter, and a polarity flippingparameter.